The project proposes to continue studies on hormonal, metabolic, and genetic factors which influence growth and maturation in the human fetus, infant, child, and adolescent. These include: (1) Hormonal changes accompanying puberty and their correlation with somatic signs, as well as clarification of the mechanism of onset of puberty in man by (a) utilizing radioimmunoassay procedures for estimation of serum and urinary FSH and LH, and serum estradiol and (b) saturation analysis for determination of serum testosterone and progesterone; (2) Exploration of quantitative aspects of the control of gonadotropin secretion in the male by testosterone and estrogen; (3) Correlation of gonadal development with ontogenesis of pituitary gonadotropin synthesis and secretion; (4) Investigation of (a) immunochemical and physicochemical interrelationships between hGH, hcs, and mCS, (b) factors affecting the secretion of hCS, and (c) identity of specific antigenic determinants on hGH and hCS; (5) Discrimination of hypothalamic from primary pituitary forms of idiopathic growth hormone deficiency, by utilizing hypothalamic-releasing factors, and clarification of relationship between growth hormone deficiency and delayed adolescence; (6) Further elucidation of the etiology, pathogenesis, and classification of anomalies of sex in man; (7) Fluorescent labeling of the Y chromosome for (a) simplifying identification of fetal cells in the maternal circulation, (b) detecting Y chromatin in small structurally abnormal sex chromosomes, and (c) prenatal determination of sex on cells in amniotic fluid; and (8) Simplification of neonatal diagnosis of congenital virilizing adrenal hyperplasia and its subsequent management, by use of a competitive protein-binding assay for plasma 17- hydroxyprogesterone.